Supports for double-walled containers



April 19, 1955 w. SOHERR 2,706,575

SUPPORTS FOR DOUBLE-WALLED CONTAINERS Filed March 6, 1951 s Sheets-Sheet 1 FIG.|

INVENTOR WILLIAM SOHERR April 19, 1955 w. SOHERR 2,706,575

SUPPORTS FOR DOUBLE-WALLED CONTAINERS Filed March 6, 1951 3 Sheets-Sheet 2 Illa 1 I i/[IA FIG. 2

INVENTOR WILLIAM S'OHERR April 19, 1955 w. SOHERR 2,706,575

SUPPORTS FOR DOUBLE-WALLED CONTAINERS Filed March 6, 1951 3 Sheets-Sheet 3 l6\ W; l6

mfiwigi? I5 1l \kq 24 INVENTOR WILLIAM SOHERR ATTORNEY United States Patent SUPPORTS FOR DOUBLE-WALLED CONTAINERS William Seherr, Mount Vernon, N. Y., assignor to Air Reduction Company, Incorporated, a corporation of New York Application March 6, 1951, Serial No. 214,071

Claims. (Cl. 220-) This invention relates to double-walled containers for the storage of liquified gases and more particularly 1s concerned with apparatus for supporting the inner vessel of such a container within the outer vessel and substantially spaced therefrom.

The most generally accepted manner heretofore employed for supporting the inner vessel in such doublewalled containers has been to suspend it from the outer vessel by long thin rods of a material having a relatively low thermal conductivity such as stainless steel. This manner of support however has one main deficiency and that is that during shipment of the containers and at other times when they are subjected to rough handling, the suspension does not satisfactorily prevent lateral relative movement of the inner vessel. Furthermore the material from which the rods must be made in order to possess satisfactory tensile strength to support the load in tension does not have the low thermal conductivity properties of other materials now available which might be used to support an equal load in compression. It has been proposed to support the inner container by supporting members which support the load in compression. However, none of this latter type of supports has made provision for preventing lateral relative movement between the inner and outer vessels nor has substantially decreased the heat gain which takes place through the support. Wood has been suggested as the material for a compression support but is not particularly satisfactory because the space between the inner and outer vessels is usually evacuated for insulating purposes and this dehydrates the wood tending to make it more brittle and substantially weaken it and lessen its life span.

The primary object of this invention is therefore to provide supports for the inner vessel of a double-walled container for the storage of liquified gases which provide resistance to substantial lateral relative movement of the inner vessel with respect to the outer vessel, which are more efiicient heat barriers than supports heretofore proposed have been, and which allow for only limited movement of the inner vessel with respect to the outer vessel because of expansion or contraction of the inner vessel.

Accordingly, a support constructed in accordance with this invention comprises a bracket secured to the inner vessel and a bracket secured to said outer vessel. A hollow member of a plastic laminate material is provided to interconnect the brackets by being secured therebetween. The hollow member is relatively loosely connected to at least one of the brackets whereby relative movement between the two vessels directly attributable to the expansion and contraction of the inner vessel is permitted but substantially all other relative movement between the two in any direction is prevented.

In one form of support contemplated by the invention, the outer bracket is secured to the outer face of the outer casing and the hollow member of plastic laminate material extends through an opening in the outer casing. In this form, the bracket is secured to the outer casing by airtight connections and is adapted to be engaged by legs for supporting the composite container.

For a more detailed description of the abovementioned form of support, which comes within the scope of this in vention, reference may be made to the accompanying drawings, in which:

Fig. 1 is an elevational view partly in section of one form of double-walled container in which the supports of my invention may be employed and illustrates the use of the preferred form of support;

Fig. 2 is an enlarged sectional view of the preferred form of support illustrated in Fig. 1; and

Fig. 3 is a sectional view on line 3-3 of Fig. 2.

The double-walled container illustrated in Fig. 1 comprises a-spherical inner vessel 10 adapted to contain a liquefied gas, which is to be stored, and an outer vessel 11 of substantially spherical shape spaced from the inner vessel. A plurality of supporting legs 12 are located beneath the under side of the outer vessel 11 and provide support for the composite container, when in an upright position. A bracket 13 is fastened to the upper end of the inner vessel and is provided for lifting the entire double-walled container for shipment. The space between the inner and outer vessels contains a number of liquefied gas conduits or pipes through which the liquefied gas may be fed into the inner vessel for storage and removed therefrom for use. As these various pipes or conduits play no part in the present invention, they need not be further described, except to say that provision is made at both of the openings in the outer vessel, through which the inlet pipe and outlet pipe extend, to maintain them normally closed by gas-tight seals. The space between the two vessels is used for insulating purposes and may be filled with insulating material, such as powdered Santocel. Furthermore, this space is usually evacuated.

The inner vessel 10 is supported within outer vessel 11 solely by a plurality of supports indicated generally at 14 in Fig. 1. These supports constitute my invention, those shown in Fig. 1 being of the preferred form and being illustrated in greater detail in the enlarged sectional view of Fig. 2 and in Fig. 3.

Referring now to Figs. 2 and 3 of the drawings, the preferred form of support comprises an inner angular bracket 15 secured, as by welding, to the outer face of inner vessel 10. A pair of side plates 16 are secured to opposite sides of bracket 15 and extend substantially below the bracket. Each is provided toward its distal edge with a hole 17. A second support bracket 18 is secured, again as by welding, substantially to the outer face of the outer vessel 11. The connection between bracket 18 and outer vessel 11 must be gas-tight to maintain the space between vessels 10 and 11 gas-tight for insulating purposes, in view of the fact that part of the support is to extend through an opening 19 in the wall of the outer vessel. Secured between inner bracket 15 and outer bracket 18, is a support assembly comprising a hollow cylinder 20 of plastic laminate material extending through opening 19, an inner support member 21, and an outer support member 22. The hollow cylindrical member 20 receives in its opposite ends reduced portions of support members 21 and 22 and is secured thereto by a number of bolts 23. Lower support member 22 is fixedly secured to bracket 18 substantially outside the outer vessel, while inner support member 21 is provided with a hole 24 through its upper end, which is adapted to be aligned with holes 17 in the side plates 16 (the upper end of member 21 extending between the side plates as seen in Fig. 3) and to be secured to the side plates by a pm extending through it and holes 17. This pin connect1on between support member 21 and side plates 16 is intended to be a relatively loose one to accommodate expansion and contraction of the inner vessel 10 when a liqurfied gas is supplied to it or removed from it.

It w1ll be clear from the above description of the preferred form of support illustrated in Figs. 1-3 that no relative movement, other than that directly attributable to the expansion and contraction of inner vessel 10, will be permltted and thus, during shipment of the container, no excessive, harmful shifting of inner vessel 10 with respect to outer vessel 11 may take place.

When the composite double-walled container is perrnanently located, it is supported by legs 12, as illustrated in Fig. l, WhlCh are adapted to be secured to or at least engage outer bracket 18 of the support. Should the double-walled container be of the tank-car type rather than the type illustrated it will be clear that legs 12 may be replaced by supporting structure which forms a part of the car body and perhaps extends throughout the length of the car.

The essential characteristic of a satisfactory support for the inner vessel of a double-walled container is that it must have a very low thermo-conductivity value, whereby it is capable of transferring very little heat and thus is an efficient heat barrier. In the form of support illustrated, the hollow cylindrical member made of a plastic laminate material forms a heat barrier because, any heat transferred from the outer vessel to the inner vessel must pass through it.

A number of materials are contemplated, from which the hollow cylindrical members may be made. Two specific examples are (l) a glass cloth laminated melamine resin bonded plastic and (2) an asbestos cloth laminated melamine resin plastic. The melamine glass laminate weighs about one-half as much as aluminum and has an average density of about .05 lb. per cubic inch. Furthermore, in compression, it has a strength exceeding that of structural steel when the load is applied normal to the lamination and, as an insulating material, is one of the best known. It resists both cold and heat and is not subject to embrittlement at temperatures below zero down to -300 F. and, additionally, its compressive strength tends to increase as the temperature is lowcred. Another, and perhaps equally important characteristic of this material, and of others which might be employed, is that it is very easily fabricated. Other filler materials beside glass cloth and asbestos, which might be used in the plastic are, for instance, paper, canvas duck, and like fibrous materials, which have good strength characteristics. While powder fillers might be used, they lack the strength of the fibrous type. Other plastics that might be used include the phenolics and ureas.

Comparative tests have shown the following q values for tension loaded rods made of stainless steel, and compression loaded melamine asbestos laminate and melamine glass laminate supports, the q value representing the heat gained per hour through the rod. For stainless steel where F equals the load carried by the rod and L is the length of rod between points of contact with the inner and outer vessels. For a melamine asbestos laminate support B. t. u./hr.

=1.07 1o B. t. u./hr.

and for a melamine glass laminate support q= 1.54X10- B. t. u./hr.

From the above, it will be apparent that the supports of this invention are between 11 and 16 times more efficient as heat barriers than conventional stainless steel supports, since F and L depend on the size or weight of the tank in either case. In general, however, the length of the plastic supports of this invention would be about one-third the lengths of the corresponding stainless steel rod supports that have been previously employed. Thus, the relative efiiciency of the supports of the invention as heat barriers with respect to the stainless steel support previously used would be approximately 4 or 5 to 1.

I claim:

1. In a double-walled container for the storage of liquified gas including an inner vessel for holding the liquified gas and an outer vessel completely surrounding the inner vessel and spaced therefrom, said outer vessel being air tight, a plurality of apparatus for supporting said inner vessel within said outer vessel and spaced therefrom each of which apparatus comprises a bracket secured to the inner vessel, a bracket secured to said outer vessel substantially outside the outer vessel, a support member fixedly secured to said last-mentioned outer bracket, an inner support member secured by a loose pin connection to the bracket secured to the inner vessel, and a hollow member of a plastic laminate material extending through an opening in the wall of the outer vessel and interconnecting said support members, the opposite ends of said hollow member overlying the adjacent ends of said support members and being secured thereto.

2. In a double-walled container for the storage of liquified gas including an inner vessel for holding the liquified gas and an outer vessel completely surrounding the inner vessel and spaced therefrom, said outer vessel being air tight, a plurality of apparatus for supporting said inner vessel within said outer vessel and spaced therefrom each of which apparatus comprises a bracket secured to the inner vessel, a bracket secured to the outer vessel substantially outside the outer vessel, an outer support member fixedly secured to said last mentioned outer bracket, an inner support member engaging the bracket secured to the inner vessel, a pair of side plates secured to opposite sides of said bracket secured to the inner vessel and receiving between them the inner end of the inner support member, a connecting pin extending through holes in said plates and said inner end of the inner support member, a number of said holes being substantially larger in diameter than the pin, and a hollow member of a plastic laminate material extending through an opening in the wall of the outer vessel and interconnecting said support members, the opposite ends of said hollow member overlying the adjacent ends of said support members and being secured thereto.

3. A double-walled container as set forth in claim 2, in which the bracket secured to said outer vessel substantially outside thereof is secured to said outer vessel by an air tight connection, and in which said outer support member is fixedly secured to the inner face of said outer bracket.

4. A double-walled container as set forth in claim 2 including supporting legs for the container, each leg engaging one of said outer brackets.

5. In a double-walled container for the storage of liquefied gas including an inner vessel for holding the liquefied gas and an outer vessel completely surrounding the inner vessel and spaced therefrom, said outer vessel being airtight, apparatus for supporting said inner vessel within said outer vessel and spaced therefrom which comprises brackets secured to said inner vessel, brackets secured to said outer vessel, a hollow compression-type supporting member of a plastic laminate material located between each bracket secured to the inner vessel and each bracket secured to said outer vessel, and means connecting each said hollow member to its pair of brackets, each said means preventing sufficient lateral relative movement between said inner bracket and said hollow supporting member to permit dislodgement of said inner bracket from said hollow supporting member but permitting limited relative movement between said inner bracket and said hollow supporting member to accommodate diflerent degrees of expansion and contraction of said vessels, and each said connecting means being free of a direct metal-to-metal joining of said brackets which it connects whereby heat transger from one bracket to the other bracket is minim1ze References Cited in the file of this patent UNITED STATES PATENTS 1,661,659 Gray Mar. 6, 1928 1,810,615 Knight June 16, 1931 2,460,355 Kornemann Feb. 1, 1949 2,467,428 Hansen et al Apr. 19 ,1949 2,495,798 Wissmiller Jan. 31, 1950 2,504,390 Caldwell, Jr. Apr. 18, 1950 2,528,780 Preston Nov. 7, 1950 2,563,118 Jackson Aug. 7, 1951 2,613,838 King Oct. 14, 1952 

